Cellulose condensation product and process for making same



Patented Nov. .5, 1929 ERlCH-'GEBAUER-UELNEGG, .'OF VIENNA, AUSTRIA, .assronon [TO :I. :ou your .,I E.;.-NnMouRs & icomrnny, or WILMINGTON, DELAWARE, A .conronarron :or

(DELAWARE No Drawing.

"' This invention relates to sulfonic acidderivative-cellulose condensation products and methods for preparing the same.

The steadily increasing technical demand for cellulose esters, which find numerous applications in the variousarts, has resulted in the production of a large number and variety of compounds of cellulose esterified with the radicals of strong as well as Weak inorganic and organic acids. So-called cellulose sulfuric acid esters have been prepared and described in the literature, but every indication points to the fact that these substances, are esters of a much degraded cellulose, such as a polysaccharide. This-view is supported by the fact that solutions of such esters exhibit strong optical polarization, and also by the fact that these esters form Water-soluble barium salts.

It is one of the objects of the present in vention to form condensation products of cellulose andsulfonic acid derivatives which will be described as the sulfonic acid esters or undegraded sulfonic acid esters of. cellulose. It is a further object of the invention to prepare compounds such as those mentioned, which have valuable properties not possessed by the substances heretofore known.

The present invention comprises sulfonic acid derivative-cellulose condensation products which are prepared by treating cellulose with a reaction mixture containing a tertiary amine and a substance which contains the following radical is a specific example of the invention., which is given merely by way of illustration and not The following the cellulose disappears. 'Under these condi- 'tions,

the reaction reaches completeness in about ducted at any has been found that by 75 minutes. The resulting viscous.

cELLuIiosE connnnsn'rron PBODUCTQAND .rnocnsfs :non MAiimGsAM-n Application filed August n, 1927. Serial N0.;214,216.

'precipitating the ester by the addition of a small amount of saturated sodium chloride solution.

Other solutions may be used for the precipitationas is well known from colloid chemist-ryprovided that the salts do not react with the ester to form insoluble salts of the ester.

In place of the chlorsulfonic acid described above the esters of chlorsulfonic acid may 7 be used in the same molecular proportions (e. g. theethyl ester, etc.), the reaction with this material going more slowly, but after about six hours the reaction is complete and the product is practically identical with that *5 formed in the example described. It has been found that, in general, substances containing the following radical Y are suitable for fise in of this invention.

In place of pyridine, it has been found that tertiary amines (e. g; dimethyl aniline), are generally suitable for use in this process, the prime prerequisite seeming to be that the amine form an easily CllSSOClfitQd. salt with chlorsulfonic acid or equivalent substances.

The esterification reactions may be consuitable preparing the esters temperature, but it working at temperatures in the neighborhood of 100 C.'the reaction is carried to completion more rapidly and more satisfactorily. Somewhat higher temperatures maybe used if desired, and if time is not a vital factor in the process such lower temperature may be used as may be, found satisfactory.

The product obtained in the-above example 100 through a spinneret into a precipitating bath i p p and a substance vluch contalns the radical nitrate. In this manner it. is possible to obta n iii is probably a pyridine salt of the sulfonic acid "with certain salts, with tormation'sof prac-' tically insolilble-metallic salts, of the esters. Such insoluble salts are formed by treatment with soluble salts of aluminum, barium, calcium andlead. 'For instance a barium salt of the ester prepared in this manner is practically insoluble in Water and is not appreciably altered even in boiling water; it is also yery resistant to diluted strong acids in the cold, and barium hydroxide solutions do not alter it materially even after boiling for several hours. It is possible to take advantage of this property of the pyridine and like salts of the esterby forcing the salt of the soluble barium salt, for exam ple barium threads of the ester.

As has been pointed out the esters or the precipitat ed bariiun saltof the amino salts thereof are soluble in water inf the sense that they form a reversible colloidal solution, which in concentrated solu-. tion is viscous. \Vhcn the solutions are dried on a suitable surface, films are formed which may be obtained in practically any desired thickness and size. The films are soluble in water but are insoluble in most organic solvents. The esters are further characterized by showing no optical rotation when a Water solution of the ester is tested.

While the condensation products of cel lulose and sulfuric or sultonic acidare spoken of as esters. it is not desired to limit this invention to any set. chemical formulas or dct'initious since, while the products are most probably esters of the type mentioned and display ester characterislics, the final composition of the products is not definitely known. 7

Suitable variations and changes may be intrmluccd into the mal'tters herein set forth, without departing from the spirit and scope of the present invention, except as set forth in the appended claims.

I claim:

l l. Thprocess for preparing suli'onic aciddeui 'at'ire-ccllulosc comlcnsaticm products which comprises treating cellulose with a reaction mixture containing a tertiary amine and a substance which comains the radical 0 said substance being capable ofsulfoinuing the cellulose.

v 2. 'Ihe process for preparing sult'omc acidaction mixture containing pyridineand a chlorsult'onic acid; 1-" I 1 at. The process for preparing sulfonic acidderivative-cellulose condensation products which comprises treating cellulose with a reaction mixture containing a tertiary amine and ethyl chlorsulfonic acid.

5. The process for preparing sulfonic acidderivative-cellulose condensation. products which comprises treating ccllulosefwith a re" action mixture containing pyridine and; ethyl chlorsulforiifac'id. i v Y i 6. The process for preparing sulfonic acid derivative-cellulose condensation I products which comprises treating cellulose with a. reaction 'niixture' 'containing a tertiary amine .being'lapable of sulfonat-ing the cellulose, and separating the condensation products from solutionby precipitating out.

7. The process torpreparing undegraded sulfuric ac-idcsters which comprises treating cellulose with a reaction mixture containing a. tertiary amine and a member of the group which consists of chlorsullonic acid and its esters.

8. A sulfonic acid-derivatire-eellulosc condensation product characterized by the fact that its barium salt is substantially insoluble in water and organic solvents.

9. chlorsuli'onic acid-cellulose condensation product characterized by the tact that its barium salt is substantially insoluble in water and organic solvents.

In Lestimonv whereof l allix my signature.

ERIQH GEBAUER-l l l'lLNEGG.

CERTIFICATE or CORRECTION.

Pmm No. 1,734,291. Granted November 5, 1929, m.

\ERICH GEBAUER-FUELNEGG.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 24, for the word "sulfonic" read "sulfuric"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 3rd day of December, A. D. 1929.

I M. J. Moore, (Seal) Acting Commissioner of Patents. 

